#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int main()
{
	int n = 0;
	int a = 0;
	float age = 0;
	scanf("%d", &n);
	int b = 0;
	for (b = 1;b<=n;b++)
	{
		scanf("%d", &a);
		age = age + a;
	}
	age= (float)age;
	printf("%0.2f\n", age/n);
	return 0;
}